198 , 
Oisr THE HEOaEAPHICAL 
less to serpents. The places of their habitation are forests, 
marshes, or even deserts, and these places have never 
perceived the influence of cultivation. Not multiplying, 
except rarely, so as to incommode man, and seeking to 
withdraw themselves from pursuit, by retiring to the un- 
cultivated places which serve for their retreat, the war 
which is made on them is usually only directed against 
individuals ; hence, the number of species, as well as of 
individuals, ought to remain almost at the point fixed by 
the general law of Nature from the beginning ; and this is 
one of the facts which it is essential to establish in physi- 
cal geography. Now, supposing that the animals of which 
we speak live still in the same places originally assigned 
to them ; that they still live in the same climate, and 
under the same conditions, it is evident that they cannot 
have been subject to any change in the course of ages : they 
present, then, more than any other living creatures, bases 
to ascertain with precision what should be understood by 
species, by constant varieties, or by varieties produced by 
local causes, or by climate. The remarks which I throw 
out will suffice to shew hovr important is the study of the 
geographical distribution of reptiles, especially of Ophi- 
dians, and the influence which this study ought to exer- 
cise on that of the geographical distribution of animals in 
general, on zoology, on geology, and on physical geogra- 
phy. 
The geographic distribution of serpents is subject to 
nearly the same laws as that of other reptile!^; flmf is to 
say, their number augments considerably towards the 
torrid zone, while they are but rare in cold regions. It 
even appears that serpents do not advance as far north- 
wards as lizards and batrachians, which are probably 
among the number of the most widely distributed reptiles.^ 
The geographic distribution of serpents, viewed in relation 
to different parts of the world, -j- presents some interesting 
^ [The Translator has seen both frogs and toads in the Orkney Islands, 
but he never heard an instance of a serpent or a lizard being found in 
that group of islands, nor yet in Zetland.] 
t I have given above, p. 92, some observations on the nature of the 
.places which serpents inhabit ; but as we do not possess any exact notices 
